MRI Findings of Renal Myxoma: A Case Report and Literature Review.

Renal myxomas are very rare benign tumors. To date, a few cases have been reported in English literature, mostly in pathology and urology journals. Thus, there are few reports on the radiological findings associated with renal myxomas. We report on the imaging findings in a case of renal myxoma in a 62-year-old male. MRI demonstrated a well-defined mass in the left renal sinus, with intermediate high signal intensity on T2-weighted images and low signal intensity on T1-weighted images. The tumor showed gradual enhancement on contrast-enhanced T1-weighted images.

Plasma Aldo-Keto Reductase Family 1 Member B10 as a Biomarker Performs Well in the Diagnosis of Nonalcoholic Steatohepatitis and Fibrosis.

We found several blood biomarkers through computational secretome analyses, including aldo-keto reductase family 1 member B10 (AKR1B10), which reflected the progression of nonalcoholic fatty liver disease (NAFLD). After confirming that hepatic AKR1B10 reflected the progression of NAFLD in a subgroup with NAFLD, we evaluated the diagnostic accuracy of plasma AKR1B10 and other biomarkers for the diagnosis of nonalcoholic steatohepatitis (NASH) and fibrosis in replication cohort. We enrolled healthy control subjects and patients with biopsy-proven NAFLD (n = 102) and evaluated the performance of various diagnostic markers. Plasma AKR1B10 performed well in the diagnosis of NASH with an area under the receiver operating characteristic (AUROC) curve of 0.834 and a cutoff value of 1078.2 pg/mL, as well as advanced fibrosis (AUROC curve value of 0.914 and cutoff level 1078.2 pg/mL), with further improvement in combination with C3. When we monitored a subgroup of obese patients who underwent bariatric surgery (n = 35), plasma AKR1B10 decreased dramatically, and 40.0% of patients with NASH at baseline showed a decrease in plasma AKR1B10 levels to below the cutoff level after the surgery. In an independent validation study, we proved that plasma AKR1B10 was a specific biomarker of NAFLD progression across varying degrees of renal dysfunction. Despite perfect correlation between plasma and serum levels of AKR1B10 in paired sample analysis, its serum level was 1.4-fold higher than that in plasma. Plasma AKR1B10 alone and in combination with C3 could be a useful noninvasive biomarker for the diagnosis of NASH and hepatic fibrosis.

Magnetic Resonance-Based Assessments Better Capture Pathophysiologic Profiles and Progression in Nonalcoholic Fatty Liver Disease.

BACKGROUND: Several noninvasive tools are available for the assessment of nonalcoholic fatty liver disease (NAFLD) including clinical and blood biomarkers, transient elastography (TE), and magnetic resonance imaging (MRI) techniques, such as proton density fat fraction (MRI-PDFF) and magnetic resonance elastography (MRE). In the present study, we aimed to evaluate whether magnetic resonance (MR)-based examinations better discriminate the pathophysiologic features and fibrosis progression in NAFLD than other noninvasive methods. METHODS: A total of 133 subjects (31 healthy volunteers and 102 patients with NAFLD) were subjected to clinical and noninvasive NAFLD evaluation, with additional liver biopsy in some patients (n=54). RESULTS: MRI-PDFF correlated far better with hepatic fat measured by MR spectroscopy (r=0.978, P<0.001) than with the TE controlled attenuation parameter (CAP) (r=0.727, P<0.001). In addition, MRI-PDFF showed stronger correlations with various pathophysiologic parameters for cellular injury, glucose and lipid metabolism, and inflammation, than the TE-CAP. The MRI-PDFF and TE-CAP cutoff levels associated with abnormal elevation of serum alanine aminotransferase were 9.9% and 270 dB/m, respectively. The MRE liver stiffness measurement (LSM) showed stronger correlations with liver enzymes, platelets, complement component 3, several clinical fibrosis scores, and the enhanced liver fibrosis (ELF) score than the TE-LSM. In an analysis of only biopsied patients, MRE performed better in discriminating advanced fibrosis with a cutoff value of 3.9 kPa than the TE (cutoff 8.1 kPa) and ELF test (cutoff 9.2 kPa). CONCLUSION: Our results suggest that MRI-based assessment of NAFLD is the best non-invasive tool that captures the histologic, pathophysiologic and metabolic features of the disease.

Contribution of cytologic examination to diagnosis of poorly differentiated thyroid carcinoma.

BACKGROUND: The cytologic diagnosis of poorly differentiated thyroid carcinoma (PDTC) is difficult because it lacks salient cytologic findings and shares cytologic features with more commonly encountered neoplasms. Due to diverse cytologic findings and paucicellularity of PDTC, standardization of cytologic diagnostic criteria is limited. The purpose of this study is to investigate and recognize diverse thyroid findings of fine needle aspiration (FNA) cytology and frozen smear cytology in diagnosis of this rare but aggressive carcinoma. METHODS: The present study included six cases of FNA cytology and frozen smears of histologically diagnosed PDTCs. RESULTS: PDTC showed cytologic overlap with well-differentiated thyroid carcinomas (WDTCs). Five of six cases showed dedifferentiation arising from well differentiated thyroid carcinomas. Only one de novo PDTC showed highly cellular smears composed of discohesive small cells, high nuclear/cytoplasmic (N/C) ratio, prominent micronucleoli, and irregular nuclei. Retrospectively reviewed, these findings are highly suspicious for PDTC. Cytologic findings of nuclear atypia, pleomorphism, and irregularity were frequently found, whereas scattered small cells were seen only in the de novo case. CONCLUSIONS: Heterogeneous cytologic findings of PDTCs are shared with those of WDTCs and contribute to difficult preoperative cytologic diagnoses. Most PDTCs show dedifferentiation from WDTCs. Albeit rare, de novo PDTC should be considered with cytology showing discohesive small cells with high N/C ratio. This will enable precise diagnosis and prompt treatment of this aggressive malignancy.

Comparison of papanicolaou smear and human papillomavirus (HPV) test as cervical screening tools: can we rely on HPV test alone as a screening method? An 11-year retrospective experience at a single institution.

BACKGROUND: The decrease in incidence of cervical dysplasia and carcinoma has not been as dramatic as expected with the development of improved research tools and test methods. The human papillomavirus (HPV) test alone has been suggested for screening in some countries. The National Cancer Screening Project in Korea has applied Papanicolaou smears (Pap smears) as the screening method for cervical dysplasia and carcinoma. We evaluated the value of Pap smear and HPV testing as diagnostic screening tools in a single institution. METHODS: Patients co-tested with HPV test and Pap smear simultaneously or within one month of each other were included in this study. Patients with only punch biopsy results were excluded because of sampling errors. A total of 999 cases were included, and the collected reports encompassed results of smear cytology, HPV subtypes, and histologic examinations. RESULTS: Sensitivity and specificity of detecting high-grade squamous intraepithelial lesion (HSIL) and squamous cell carcinoma (SCC) were higher for Pap smears than for HPV tests (sensitivity, 97.14%; specificity, 85.58% for Pap smears; sensitivity, 88.32%; specificity, 54.92% for HPV tests). HPV tests and Pap smears did not differ greatly in detection of low-grade squamous intraepithelial lesion (85.35% for HPV test, 80.31% for Pap smears). When atypical glandular cells were noted on Pap smears, the likelihood for histologic diagnosis of adenocarcinoma following Pap smear was higher than that of high-risk HPV test results (18.8 and 1.53, respectively). CONCLUSIONS: Pap smears were more useful than HPV tests in the diagnosis of HSIL, SCC, and glandular lesions.

Human Immunodeficiency Virus-Associated Gastrointestinal Kaposi's Sarcoma: A Case Report.

Kaposi's sarcoma (KS) is a multicentric human immunodeficiency virus-associated neoplasm characterized by multiple vascular nodules in the skin, mucous membranes, and viscera. Gastrointestinal acquired immunodeficiency syndrome (AIDS)-related KS is the most common visceral involvement reported in disseminated disease. Here, we present the findings of a rare case of KS involving multiple organs with abdominal pain and active bleeding in the colon. Multiple intraluminal lesions were found in the terminal ileum, sigmoid colon, and rectum by ileocolonoscopy, and in the jejunum and ileum by fluoroscopy. Abdominopelvic CT revealed multiple enhanced flat lesions in the ileum and enlarged lymph nodes. The diagnosis was confirmed by histopathology, and antiretroviral therapy was initiated as the treatment of choice for KS. Owing to the increasing number of AIDS patients, it is essential for radiologists and clinicians to be aware of the imaging characteristics of KS to protect physicians from indiscriminate exposure to AIDS.

Primary carcinoid tumor in the external auditory canal.

A 39-year-old man visited the department of otolaryngology due to an ongoing hearing disturbance that had lasted for 1 year. Temporal bone computed tomography revealed soft tissue density nearly obliterating the left external auditory canal (EAC). The mass was composed of sheets of round tumor cells containing moderate amounts of fine granular cytoplasm and salt and pepper chromatin. Neither mitosis nor necrosis was found. The Ki-67 proliferation index was less than 2%. Cells were positive for CD56 and synaptophysin but negative for chromogranin, cytokeratin (CK) 20, and CK7. Based on these findings, the tumor was diagnosed as a carcinoid tumor, well differentiated neuroendocrine carcinoma, grade 1 (G1) according to current World Health Organization (WHO) classification of head and neck tumors; and a neuroendocrine tumor, G1 according to neuroendocrine neoplasm (NEN)-2018 WHO standard classification. He remained free of local recurrence and metastasis after 20 months of follow up. To date, only six cases of primary NENs in the EAC have been reported. Metastatic tumor should be included in the differential diagnoses. Because of its rarity, the prognosis and treatment have not yet been clarified.

Frozen Cytology of Meningeal Malignant Solitary Fibrous Tumor/Hemangiopericytoma.

A 51-year-old woman presented with severe dizziness. The brain magnetic resonance image revealed a 5.5 cm multiloculated mass with a thick rim in the left temporal lobe. Cytological examination of frozen diagnosis of the mass showed hypercellular sheets of round and rhabdoid cells in a hemorrhagic background, and two mitotic figures were observed. Histologically, the excised dura-based mass consisted of predominantly round cells with small foci of rhabdoid tumor cells in a pseudoalveolar pattern in a hemorrhagic background, and the cells showed nuclear positivity for signal transducer and activator of transcription 6 as well as frequent mitosis. The mass was diagnosed as a grade 3 solitary fibrous tumor (SFT)/hemangiopericytoma (HPC). The cytological diagnosis of SFT/HPC is challenging because of the heterogeneous cytological findings, such as histological heterogeneity, and because there are no standardized cytological criteria for malignant SFT/HPC. Cytological findings, such as singly scattered small cells, hypercellularity, rare ropy collagen, and round and rhabdoid cells with pseudoalveolar pattern, may assist in the diagnosis of malignant SFT/HPC.

Primary Necrobiotic Xanthogranulomatous Sialadenitis with Submandibular Gland Localization without Skin Involvement.

Necrobiotic xanthogranulomatous reaction is a multiorgan, non-Langerhans cell histiocytosis with an unknown etiology. Occurrence in the salivary gland is extremely rare. We recently identified a case of necrobiotic xanthogranulomatous sialadenitis in a 73-year-old Korean woman who presented with a painless palpable lesion in the chin. There was no accompanying cutaneous lesion. Partial resection and subsequent wide excision with neck dissection were performed. Pathological examination showed a severe inflammatory lesion that included foamy macrophages centrally admixed with neutrophils, eosinophils, lymphocytes, plasma cells, and scattered giant cells, as well as necrobiosis. During the 12-month postoperative period, no grossly remarkable change in size was noted. Necrobiotic xanthogranulomatous inflammation may be preceded by or combined with hematologic malignancy. Although rare, clinicians and radiologists should be aware that an adhesive necrobiotic xanthogranuloma in the salivary gland may present with a mass-like lesion. Further evaluation for hematologic disease and close follow-up are needed when a pathologic diagnosis is made.

Intraoperative Frozen Cytology of Central Nervous System Neoplasms: An Ancillary Tool for Frozen Diagnosis.

BACKGROUND: Pathologic diagnosis of central nervous system (CNS) neoplasms is made by comparing light microscopic, immunohistochemical, and molecular cytogenetic findings with clinicoradiologic observations. Intraoperative frozen cytology smears can improve the diagnostic accuracy for CNS neoplasms. Here, we evaluate the diagnostic value of cytology in frozen diagnoses of CNS neoplasms. METHODS: Cases were selected from patients undergoing both frozen cytology and frozen sections. Diagnostic accuracy was evaluated. RESULTS: Four hundred and fifty-four cases were included in this retrospective single-center review study covering a span of 10 years. Five discrepant cases (1.1%) were found after excluding 53 deferred cases (31 cases of tentative diagnosis, 22 cases of inadequate frozen sampling). A total of 346 cases of complete concordance and 50 cases of partial concordance were classified as not discordant cases in the present study. Diagnostic accuracy of intraoperative frozen diagnosis was 87.2%, and the accuracy was 98.8% after excluding deferred cases. Discrepancies between frozen and permanent diagnoses (n = 5, 1.1%) were found in cases of nonrepresentative sampling (n = 2) and misinterpretation (n = 3). High concordance was observed more frequently in meningeal tumors (97/98, 99%), metastatic brain tumors (51/52, 98.1%), pituitary adenomas (86/89, 96.6%), schwannomas (45/47, 95.8%), high-grade astrocytic tumors (47/58, 81%), low grade astrocytic tumors (10/13, 76.9%), non-neoplastic lesions (23/36, 63.9%), in decreasing frequency. CONCLUSIONS: Using intraoperative cytology and frozen sections of CNS tumors is a highly accurate diagnostic ancillary method, providing subtyping of CNS neoplasms, especially in frequently encountered entities.

Strongyloidiasis Presenting as Yellowish Nodules in Colonoscopy of an Immunocompetent Patient.

Strongyloides stercoralis is endemic to tropical and subtropical regions, and infections are usually asymptomatic. However, immunocompromised patients, such as those receiving immunosuppressive therapy, high-dose steroids, or chemotherapy, can develop fatal hyperinfections. An 84-year-old man without any symptoms was diagnosed with strongyloidiasis during a regular screening colonoscopy. His medical history only involved a gastric endoscopic submucosal dissection for early gastric cancer 6 months previously. Few cases have been published about asymptomatic strongyloidiasis diagnosed in an immunocompetent host via endoscopic mucosal resection with characteristic colonoscopic findings. We report a case of colon-involved asymptomatic strongyloidiasis with specific colonic findings of yellowish-white nodules. This finding may be an important marker of S. stercoralis infection, which could prevent hyperinfections.

Squamous Cell Carcinoma of the Extrahepatic Common Hepatic Duct.

We report a rare case of hilar squamous cell carcinoma. A 62-year-old Korean woman complaining of nausea was referred to our hospital. Her biliary computed tomography revealed a 28 mm-sized protruding solid mass in the proximal common bile duct. The patient underwent left hemihepatectomy with S1 segmentectomy and segmental excision of the common bile duct. Microscopically, the tumor was a moderately differentiated squamous cell carcinoma of the extrahepatic bile duct, without any component of adenocarcinoma or metaplastic portion in the biliary epithelium. Immunohistochemically, the tumor was positive for cytokeratin (CK) 5/6, CK19, p40, and p63. Squamous cell carcinoma of the extrahepatic bile duct is rare. To date, only 24 cases of biliary squamous cell carcinomas have been reported. Here, we provide a clinicopathologic review of previously reported extrahepatic bile duct squamous cell carcinomas.

Endobiliary radiofrequency ablation for distal extrahepatic cholangiocarcinoma: A clinicopathological study.

BACKGROUND: Most patients with distal extrahepatic cholangiocarcinoma have developed jaundice or cholangitis at the time of initial diagnosis, which can delay surgery. We aim to evaluate the actual EB-RFA ablation volume and validated the clinical feasibility of preoperative endobiliary radiofrequency ablation (EB-RFA) for resectable distal extrahepatic cholangiocarcinoma. METHODS: The medical records of patients who underwent EB-RFA from July 2016 to June 2017 at a single tertiary academic medical center were reviewed. Inclusion criteria were patients with resectable distal extrahepatic cholangiocarcinoma who required preoperative biliary decompression. Clinical outcomes of EB-RFA were reviewed retrospectively and the surgical specimens were reevaluated. RESULTS: Of the eight patients who required a delayed operation, preoperative EB-RFA was successfully performed without serious complications including peritonitis, hemobilia, or perforation. Although curative resection was attempted in all patients, one patient underwent open and closure due to hepatic metastasis. Seven patients underwent curative surgical resection and the histology revealed that median maximal ablation depth was 4.0 mm (range, 1-6) and median effective ablation length (histological ablation length/fluorosocopic ablation length) was 72.0% (range, 42.1-95.3). CONCLUSIONS: EB-RFA partially ablated human cancer tissue and preoperative EB-RFA might be a safe and feasible in patients with distal extrahepatic cholangiocarcinoma who require a delayed operation. Ablation of the target lesion longer than the estimated length by fluoroscopy may improve the efficacy of EB-RFA.

[Primary Hepatic Schwannoma].

A primary benign schwannoma of the liver is extremely rare. Only 30 cases have been reported in the medical literature worldwide, and only one case has been reported in Korea previously. A 56-year-old man was admitted to Gil Medical Center with incidental findings of a hepatic mass by abdominal computed tomography. The computed tomography and magnetic resonance image revealed a 3×2 cm-sized solid mass in the left lobe of the liver. Histological examination confirmed the diagnosis of a benign schwannoma, proven by positive immunoreaction with the neurogenic marker S-100 protein and a negative response to CD34, CD117, and smooth muscle actin. We report a primary benign schwannoma of the liver and review the literature.

The efficacy of real-time colour Doppler flow imaging on endoscopic ultrasonography for differential diagnosis between neoplastic and non-neoplastic gallbladder polyps.

OBJECTIVES: We evaluated the usefulness of real-time colour Doppler flow (CDF) endoscopic ultrasonography (EUS) for differentiating neoplastic gallbladder (GB) polyps from non-neoplastic polyps. METHODS: Between August 2014 and December 2016, a total of 233 patients with GB polyps who underwent real-time CDF-EUS were consecutively enrolled in this prospective study. CDF imaging was subjectively categorized for each patient as: strong CDF pattern, weak CDF pattern and no CDF pattern. RESULTS: Of the 233 patients, 115 underwent surgical resection. Of these, there were 90 cases of non-neoplastic GB polyps and 23 cases of neoplastic GB polyps. In a multivariate analysis, a strong CDF pattern was the most significant predictive factor for neoplastic polyps; sensitivity, specificity, positive predictive value, negative predictive value and accuracy were 52.2 %, 79.4 %, 38.7 %, 86.9 % and 73.9 %, respectively. Solitary polyp and polyp size were associated with an increased risk of neoplasm. CONCLUSIONS: The presence of a strong CDF pattern as well as solitary and larger polyps on EUS may be predictive of neoplastic GB polyps. As real-time CDF-EUS poses no danger to the patient and requires no additional equipment, it is likely to become a supplemental tool for the differential diagnosis of GB polyps. KEY POINTS: • Differential diagnosis between neoplastic polyps and non-neoplastic polyps of GB is limited. • The use of real-time CDF-EUS was convenient, with high agreement between operators. • The real-time CDF-EUS is helpful in differential diagnosis of GB polyps.

Skull Metastasis of Gastric Gastrointestinal Stromal Tumor Successfully Managed by Surgery.

Gastrointestinal stromal tumors (GISTs) are rare, but are the most common mesenchymal neoplasm of the gastrointestinal tract. The most common sites of metastasis are liver and peritoneum, while bone metastasis is rare. We report on a patient with skull metastasis after seven years of treatment with imatinib for metastatic GIST. She underwent metastasectomy consisting of craniectomy with excision of the mass, and cranioplasty and continued treatment with imatinib and sunitinib, without evidence of cranial recurrence. She died of pneumonia sepsis one year after metastasectomy. Skull metastasis of GIST is a very rare presentation, and an aggressive multidisciplinary approach should be considered whenever possible.

Mediastinal Tuberculous Lymphadenitis Diagnosed by Endosonographic Fine Needle Aspiration.

Isolated mediastinal tuberculous lymphadenitis is clinically rare. Its clinical presentation may mimic an esophageal submucosal tumor by extrinsic compression. A 26-year-old woman was referred to our hospital for an esophageal subepithelial tumor. A 15×10 mm sized subepithelial lesion was found 30 cm from the upper incisors on esophagogastroduodenoscopy. We diagnosed the lesion as a submucosal tumor, and performed endoscopic ultrasonography-guided fine needle aspiration for a pathologic diagnosis. The histologic examination revealed granulomatous inflammation consistent with tuberculosis. We suggest that the use of endoscopic ultrasonography and fine needle aspiration may be helpful in making an early diagnosis and planning for an optimal treatment.